textproduct: Quad Cities

KEY MESSAGES

- Storm chances ramp up again today for portions of the area, as the battle between heat and convection continues(and will continue through at least mid week). Daily severe storm risks also continue with high instability possibly through at least Tuesday.

- A Heat Advisory posted for today for over the southern half of the area with heat indices 100 or higher. Depending on clouds and storms, Monday may be just as hot.

- Cooler temperatures may occur later in the week and into next weekend if the warm dome of air can get shunted off to the southwest.

SHORT TERM /THROUGH TONIGHT/

Issued at 300 AM CDT Sun Aug 9 2026

Challenging near term with respect to convective trends and possible evolution, as well as temperatures and maximum values. The clusters of elevated convection ongoing acrs southwest into central IA being fed by profiler indicated southwest 25-35+ KT H85 MB jet is not being handled well/underdone by the CAMs. With the LLJ expected to feed eastward this way, some of that activity would seem to make it acrs the area this morning. Not erode suddenly or dive south into MO after 12z like some CAMs suggest. Even if this activity diurnally wanes into our area of concern by mid morning, eyes turn to the ongoing storm cluster and associated short wave aloft now over north central SD and the THTA-E building thermal gradient that it will look to propagate along southeastward toward the southern third of WI by early afternoon. A southwest tailing portion of this potential MCS could clip at least the northeast third of the DVN CWA by midday and early afternoon. As it does, it very well could be severe with damaging winds and meso-vortice tornadoes if the fcst sounding 30-40 KT effective shear values and building MLCAPEs by that time up to at least 3000 J/kg verify. How far southwest acrs the rest of the CWA this MCS may try to develop toward is uncertain and the soundings do indicate a building EML as you head that way.

In the wake of this convective system, there may not be much more storm activity for the rest of the afternoon and early evening. This may allow for cloud debris to erode and south winds to warm air and moisture advect at least acrs areas along and south of I-80. Good thermal guidance agreement suggesting these areas to recover back into the upper 80s to near 90 degrees, with sfc DPTs at least into the mid 70s. This allows these areas to attaining heat index readings of a 100 to near 105. Despite the chance for cloud cover, storm outflow, and even increased western wildfire smoke aloft tempering the ambient temp warm up potential, have leaned toward the cautious side and issued a Heat Advisory for this afternoon for areas generally along and south of I-80.

Tonight...with another short wave dropping down acrs the western GRT LKS, several models and ensembles develop strong evening convection acrs northern IL into lower MI as a renewed LLJ impinges on a lingering storm outflow boundary or even a type of sfc front acrs those areas. As this activity will look to feed southward, some risk of the western end of this activity affecting the eastern DVN CWA into the overnight period. Hopefully the brunt of this activity stays just off to the east of the local area of concern. Late night toward Monday morning, another round of general WAA may produce sctrd showers and thunderstorms acrs MO and into the southern DVN CWA, but these should not be strong at least thru 12z Mon looking at the shear and lapse rates.

LONG TERM /MONDAY THROUGH SATURDAY/

Issued at 300 AM CDT Sun Aug 9 2026

Monday...Another day of building heat to potentially values needing another heat headline, but with the same uncertainty of convection and associated debris limiting ambient temp warm up in places. Thus will take heat headline issuance day-by-day. Right now for Monday and Monday night, the local area will continue under the storm track but may be in between the more prime organized convective zones of the northern/central plains and especially just off to the east of the area extending to the eastern OH RVR Valley. Saying that, still plenty enough energy locally to fuel strong to severe storms if they get going. Bouts of heavy rain may also start to add up, as will be the case into Thursday.

Tuesday through Saturday...With the flattening ridge transition, the local area may be under the battle zone of the LLVL thermal gradient and upper level short wave propagation path for almost daily chance of showers and storms for much of the week and even into the weekend. This deep summer-like MCS-track for much of the week from the central plains over to the southern GRT LKS and OH RVR Valley may add up to quite a bit of rainfall by Friday. At least temps look cooler by late week and into the weekend as well, with a day or two possibly held down in the 70s with cloud cover and east winds.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 620 AM CDT Sun Aug 9 2026

Showers and storms will continue to push east into the area this morning. Confidence is greatest at KCID and KDBQ to warrant prevailing shower mention and TEMPO for thunder. Watching for some evolution to wind upstream into far N Iowa, which if occurs could roll ESE and result in some strong to isolated severe wind risk for KCID, KDBQ and possibly even KMLI from 15z-18z. Late this afternoon and evening in the wake of the earlier storms there is some uncertainty on additional development, although a ramping nocturnal LLJ and boundaries will support a chance particularly 00z-05z and have handled with general PROB30 mention at the sites. Winds outside of any storms or even possible wake low surges will generally be from the south to southeast at 5-15 kt, becoming light northeast late in the TAF cycle.

DVN WATCHES/WARNINGS/ADVISORIES

IA...Heat Advisory from noon today to 8 PM CDT this evening for IAZ063>065-067-068-076>078-087>089-098-099. IL...Heat Advisory from noon today to 8 PM CDT this evening for ILZ015-016-024>026-034-035. MO...Heat Advisory from noon today to 8 PM CDT this evening for MOZ009-010.